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2013-08-30block: Remove redundant assertionKevin Wolf
The failing condition is checked immediately before the assertion, so keeping the assertion is kind of redundant. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-08-22aio / timers: Switch entire codebase to the new timer APIAlex Bligh
This is an autogenerated patch using scripts/switch-timer-api. Switch the entire code base to using the new timer API. Note this patch may introduce some line length issues. Signed-off-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22block: Produce zeros when protocols reading beyond end of fileMORITA Kazutaka
While Asias is debugging an issue creating qcow2 images on top of non-file protocols. It boils down to this example using NBD: $ qemu-io -c 'open -g nbd+unix:///?socket=/tmp/nbd.sock' -c 'read -v 0 512' Notice the open -g option to set bs->growable. This means you can read/write beyond end of file. Reading beyond end of file is supposed to produce zeroes. We rely on this behavior in qcow2_create2() during qcow2 image creation. We create a new file and then write the qcow2 header structure using bdrv_pwrite(). Since QCowHeader is not a multiple of sector size, block.c first uses bdrv_read() on the empty file to fetch the first sector (should be all zeroes). Here is the output from the qemu-io NBD example above: $ qemu-io -c 'open -g nbd+unix:///?socket=/tmp/nbd.sock' -c 'read -v 0 512' 00000000: ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ................ 00000010: ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ................ 00000020: ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ................ ... We are not zeroing the buffer! As a result qcow2 image creation on top of protocols is not guaranteed to work even when file creation is supported by the protocol. [Adapted this patch to use bs->zero_beyond_eof. -- Stefan] Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22block: Introduce bs->zero_beyond_eofAsias He
In 4146b46c42e0989cb5842e04d88ab6ccb1713a48 (block: Produce zeros when protocols reading beyond end of file), we break qemu-iotests ./check -qcow2 022. This happens because qcow2 temporarily sets ->growable = 1 for vmstate accesses (which are stored beyond the end of regular image data). We introduce the bs->zero_beyond_eof to allow qcow2_load_vmstate() to disable ->zero_beyond_eof temporarily in addition to enable ->growable. [Since the broken patch "block: Produce zeros when protocols reading beyond end of file" has not been merged yet, I have applied this fix *first* and will then apply the next patch to keep the tree bisectable. -- Stefan] Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-19block: stop relying on io_flush() in bdrv_drain_all()Stefan Hajnoczi
If a block driver has no file descriptors to monitor but there are still active requests, it can return 1 from .io_flush(). This is used to spin during synchronous I/O. Stop relying on .io_flush() and instead check QLIST_EMPTY(&bs->tracked_requests) to decide whether there are active requests. This is the first step in removing .io_flush() so that event loops no longer need to have the concept of synchronous I/O. Eventually we may be able to kill synchronous I/O completely by running everything in a coroutine, but that is future work. Note this patch moves bs->throttled_reqs initialization to bdrv_new() so that bdrv_requests_pending(bs) can safely access it. In practice bs is g_malloc0() so the memory is already zeroed but it's safer to initialize the queue properly. We also need to fix up block/stream.c:close_unused_images() to prevent traversing a dangling pointer while it rearranges the backing file chain. This is necessary since the new bdrv_drain_all() traverses the backing file chain. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-19block: ensure bdrv_drain_all() works during bdrv_delete()Stefan Hajnoczi
In bdrv_delete() make sure to call bdrv_make_anon() *after* bdrv_close() so that the device is still seen by bdrv_drain_all() when iterating bdrv_states. Cc: qemu-stable@nongnu.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-29block: Repair the throttling code.Benoît Canet
The throttling code was segfaulting since commit 02ffb504485f0920cfc75a0982a602f824a9a4f4 because some qemu_co_queue_next caller does not run in a coroutine. qemu_co_queue_do_restart assume that the caller is a coroutinne. As suggested by Stefan fix this by entering the coroutine directly. Also make sure like suggested that qemu_co_queue_next() and qemu_co_queue_restart_all() can be called only in coroutines. Signed-off-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-26block: Allow "driver" option on the top levelKevin Wolf
This is traditionally -drive format=..., which is now translated into the new driver option. This gives us a more consistent way to select the driver of BlockDriverStates that can be used in QMP context, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-19block: fix bdrv_read_unthrottled()Peter Lieven
Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-19block: add bdrv_write_zeroes()Peter Lieven
Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-15block: Add return value for bdrv_flush_all()Kevin Wolf
bdrv_flush() can fail, and bdrv_flush_all() should return an error as well if this happens for a block device. It returns the first error return now, but still at least tries to flush the remaining devices even in error cases. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-15block: Don't parse protocol from file.filenameKevin Wolf
One of the major reasons for doing something new for -blockdev and blockdev-add was that the old block layer code parses filenames instead of just taking them literally. So we should really leave it untouched when it's passing using the new interfaces (like -drive file.filename=...). This allows opening relative file names that contain a colon. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-05block: fix bdrv_flush() ordering in bdrv_close()Stefan Hajnoczi
Since 80ccf93b we flush the block device during close. The bdrv_drain_all() call should come before bdrv_flush() to ensure guest write requests have completed. Otherwise we may miss pending writes when flushing. Call bdrv_drain_all() again for safety as the final step after bdrv_flush(). This should not be necessary but we can be paranoid here in case bdrv_flush() left I/O pending. Cc: qemu-stable@nongnu.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28block: change default of .has_zero_init to 0Peter Lieven
.has_zero_init defaults to 1 for all formats and protocols. this is a dangerous default since this means that all new added drivers need to manually overwrite it to 0 if they do not ensure that a device is zero initialized after bdrv_create(). if a driver needs to explicitly set this value to 1 its easier to verify the correctness in the review process. during review of the existing drivers it turned out that ssh and gluster had a wrong default of 1. both protocols support host_devices as backend which are not by default zero initialized. this wrong assumption will lead to possible corruption if qemu-img convert is used to write to such a backend. vpc and vmdk also defaulted to 1 altough they support fixed respectively flat extends. this has to be addresses in separate patches. both formats as well as the mentioned ssh and gluster are turned to the default of 0 with this patch for safety. a similar problem with the wrong default existed for iscsi most likely because the driver developer did oversee the default value of 1. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28block: add bdrv_add_before_write_notifier()Stefan Hajnoczi
The bdrv_add_before_write_notifier() function installs a callback that is invoked before a write request is processed. This will be used to implement copy-on-write point-in-time snapshots where we need to copy out old data before overwriting it. Note that BdrvTrackedRequest is moved to block_int.h since it is passed to .notify() functions. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-24block: Always enable discard on the protocol levelKevin Wolf
Turning on discard options in qcow2 doesn't help a lot when the discard requests that it issues are thrown away by the raw-posix layer. This patch always enables discard functionality on the protocol level so that it's the image format's responsibility to send (or not) discard requests. Requests sent by the guest will be allowed or ignored by the top level BlockDriverState, which depends on the discard=... option like before. In particular, this means that even without specifying options, the qcow2 default of discarding deleted snapshots actually takes effect now, both for qemu and qemu-img. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-17block: bdrv_reopen_prepare(): don't use QERR_OPEN_FILE_FAILEDLuiz Capitulino
The call to drv->bdrv_reopen_prepare() can fail due to reasons other than an open failure. Unfortunately, we can't use errno nor -ret, cause they are not always set. Stick to a generic error message then. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Kevin Wolf <kwolf@redhat.com>
2013-06-06blkdebug: Add BLKDBG_FLUSH_TO_OS/DISK eventsKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-04block: move qmp and info dump related code to block/qapi.cWenchao Xia
This patch is a pure code move patch, except following modification: 1 get_human_readable_size() is changed to static function. 2 dump_human_image_info() is renamed to bdrv_image_info_dump(). 3 in qmp_query_block() and qmp_query_blockstats, use bdrv_next(bs) instead of direct traverse of global array 'bdrv_states'. 4 collect_snapshots() and collect_image_info() are renamed, unused parameter *fmt in collect_image_info() is removed. 5 code style fix. To avoid conflict and tip better, macro in header file is BLOCK_QAPI_H instead of QAPI_H. Now block.h and snapshot.h are at the same level in include path, block_int.h and qapi.h will both include them. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-04block: move snapshot code in block.c to block/snapshot.cWenchao Xia
All snapshot related code, except bdrv_snapshot_dump() and bdrv_is_snapshot(), is moved to block/snapshot.c. bdrv_snapshot_dump() will be moved to another file later. bdrv_is_snapshot() is not related with internal snapshot. It also fixes small code style errors reported by check script. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-04block: drop bs_snapshots global variableStefan Hajnoczi
The bs_snapshots global variable points to the BlockDriverState which will be used to save vmstate. This is really a savevm.c concept but was moved into block.c:bdrv_snapshots() when it became clear that hotplug could result in a dangling pointer. While auditing the block layer's global state I came upon bs_snapshots and realized that a variable is not necessary here. Simply find the first BlockDriverState capable of internal snapshots each time this is needed. The behavior of bdrv_snapshots() is preserved across hotplug because new drives are always appended to the bdrv_states list. This means that calling the new find_vmstate_bs() function is idempotent - it returns the same BlockDriverState unless it was hot-unplugged. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-04block: add block driver read only whitelistFam Zheng
We may want to include a driver in the whitelist for read only tasks such as diagnosing or exporting guest data (with libguestfs as a good example). This patch introduces a readonly whitelist option, and for backward compatibility, the old configure option --block-drv-whitelist is now an alias to rw whitelist. Drivers in readonly list is only permitted to open file readonly, and returns -ENOTSUP for RW opening. E.g. To include vmdk readonly, and others read+write: ./configure --target-list=x86_64-softmmu \ --block-drv-rw-whitelist=qcow2,raw,file,qed \ --block-drv-ro-whitelist=vmdk Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-05-14block: Add hint to -EFBIG error messageKevin Wolf
The limit of qcow2 files at least depends on the cluster size. If the image format has a cluster_size option, suggest to increase it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-22block: Fix build with tracing enabledKevin Wolf
filename was still uninitialised when it's used as a parameter to a tracing function, so let's move the initialisation. Also, commit c2ad1b0c forgot to add a NULL check, which this patch adds while we're at it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Tested-by: Andreas Färber <afaerber@suse.de> Message-id: 1366645720-11384-1-git-send-email-kwolf@redhat.com Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-22block: Allow overriding backing.file.filenameKevin Wolf
If a filename is passed in the driver-specific options from the command line, the backing file path from the image is ignored now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22block: Remove filename parameter from .bdrv_file_open()Kevin Wolf
It is unused now in all block drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22block: Enable filename optionKevin Wolf
This allows using the file.filename option instead of the string that comes from -drive file=... and is passed around as a separate parameter. The goal is to get rid of this parameter and use the options QDict more consistently. With this option you can access not only the top-level image, but specify a filename for the backing file (currently only if no backing file exists, but we'll allow overriding it later) Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22block: Add driver-specific options for backing filesKevin Wolf
Options starting in "backing." are passed to the backing file now. If you don't need to specify the filename for the backing file, you can add it on the command line instead of in the image file: $ qemu-nbd -t /tmp/test.img $ qemu-img create -f qcow2 empty.qcow2 1G $ qemu-system-x86_64 -drive file=empty.qcow2,backing.file.driver=nbd,\ backing.file.host=localhost Note that this doesn't override the backing filename from the image. If the image has one, this will fail because NBD doesn't want the options and a filename at the same time. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22block: Fail gracefully when using a format driver on protocol levelKevin Wolf
Specifying the wrong driver could fail an assertion: $ qemu-system-x86_64 -drive file.driver=qcow2,file=x qemu-system-x86_64: block.c:721: bdrv_open_common: Assertion `file != ((void *)0)' failed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-04-15block: Introduce bdrv_pwritev() for qcow2_save_vmstateKevin Wolf
Directly pass the QEMUIOVector on instead of linearising it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-15block: Introduce bdrv_writev_vmstateKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-05block: clean up I/O throttling wait_time codeStefan Hajnoczi
The wait_time variable is in seconds. Reflect this in a comment and use NANOSECONDS_PER_SECOND instead of BLOCK_IO_SLICE_TIME * 10 (which happens to have the right value). Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-By: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-04-05block: drop duplicated slice extension codeStefan Hajnoczi
The current slice is extended when an I/O request exceeds the limit. There is no need to extend the slice every time we check a request. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-By: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-04-05block: keep I/O throttling slice time constantStefan Hajnoczi
It is not necessary to adjust the slice time at runtime. We already extend the current slice in order to carry over accounting into the next slice. Changing the actual slice time value introduces oscillations. The guest may experience large changes in throughput or IOPS from one moment to the next when slice times are adjusted. Reported-by: Benoît Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-By: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-04-05block: fix I/O throttling accounting blind spotStefan Hajnoczi
I/O throttling relies on bdrv_acct_done() which is called when a request completes. This leaves a blind spot since we only charge for completed requests, not submitted requests. For example, if there is 1 operation remaining in this time slice the guest could submit 3 operations and they will all be submitted successfully since they don't actually get accounted for until they complete. Originally we probably thought this is okay since the requests will be accounted when the time slice is extended. In practice it causes fluctuations since the guest can exceed its I/O limit and it will be punished for this later on. Account for I/O upon submission so that I/O limits are enforced properly. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-By: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-03-28block: Fix direct use of protocols as driver for bdrv_open()Kevin Wolf
bdrv_open_common() implements direct use of protocols by copying the pre-opened BlockDriverStates to bs using bdrv_swap(). It did however first set some fields in bs, which end up in file after the swap. When bdrv_open() destroys file, it appears to be open, and because it isn't, qemu could segfault while trying to close it. Reorder the operations to return immediately in such cases so that file is correctly detected as closed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-22block: Allow omitting the file name when using driver-specific optionsKevin Wolf
After this patch, using -drive with an empty file name continues to open the file if driver-specific options are used. If no driver-specific options are specified, the semantics stay as it was: It defines a drive without an inserted medium. In order to achieve this, bdrv_open() must be made safe to work with a NULL filename parameter. The assumption that is made is that only block drivers which implement bdrv_parse_filename() support using driver specific options and could therefore work without a filename. These drivers must make sure to cope with NULL in their implementation of .bdrv_open() (this is only NBD for now). For all other drivers, the block layer code will make sure to error out before calling into their code - they can't possibly work without a filename. Now an NBD connection can be opened like this: qemu-system-x86_64 -drive file.driver=nbd,file.port=1234,file.host=::1 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22block: Rename variable to avoid shadowingKevin Wolf
bdrv_open() uses two different variables called options. Rename one of them to avoid confusion and to allow the outer one to be accessed everywhere. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22block: Introduce .bdrv_parse_filename callbackKevin Wolf
If a driver needs structured data and not just a string, it can provide a .bdrv_parse_filename callback now that parses the command line string into separate options. Keeping this separate from .bdrv_open_filename ensures that the preferred way of directly specifying the options always works as well if parsing the string works. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22block: Pass bdrv_file_open() options to block driversKevin Wolf
Specify -drive file.option=... on the command line to pass the option to the protocol instead of the format driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22block: Add options QDict to bdrv_file_open() prototypesKevin Wolf
The new parameter is unused yet. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22Revert "block: complete all IOs before .bdrv_truncate"Peter Lieven
brdv_truncate() is also called from readv/writev commands on self- growing file based storage. this will result in requests waiting for theirselves to complete. This reverts commit 9a665b2b8640e464f0a778216fc2dca8d02acf33. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-03-19block: fix BDRV_O_SNAPSHOT protocol detectionStefan Hajnoczi
realpath(3) is used to get an absolute path to the image file when creating a -drive snapshot=on temporary qcow2. This does not work for protocols since their filenames ("proto:foo:...") do not correspond to file system paths. Commit 7c96d46ec245d73fd76726588409f9abe4bd5dc1 ("Let snapshot work with protocols") skipped realpath(3) for protocols. Later on the "raw" format was introduced and broke the check. Use path_has_protocol(filename) to decide if this image uses a protocol or a filename. Reported-by: Richard Jones <rjones@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-03-15block: add bdrv_get_aio_context()Stefan Hajnoczi
For now bdrv_get_aio_context() is just a stub that calls qemu_aio_get_context() since the block layer is currently tied to the main loop AioContext. Add the stub now so that the block layer can begin accessing its AioContext. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2013-03-15block: Add options QDict to bdrv_open_common()Kevin Wolf
The options are passed down to the block drivers, which are supposed to remove all options they have processed. Anything that is left over in the end is an unknown option and results in an error. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15block: Add options QDict to bdrv_open() prototypeKevin Wolf
It doesn't do anything yet except storing the options QDict in the BlockDriverState. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15block: Add options QDict to .bdrv_open()Kevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-04block: for HMP commit() operations on 'all', skip non-COW drivesJeff Cody
During a commit of 'all' using the HMP non-live commit, the operation is aborted and returns error on the first error enountered. When non-COW drives are in use (e.g. ejected floppy, cdrom, or drives without a backing parent), that means a commit all will return an error of either -ENOMEDIUM or -ENOTSUP. This is not desirable, so for the 'all' commit case, only attempt the commit if both bs->drv and bs->backing_hd are present. More succinctly: 'commit all' now means a commit on all COW drives. This means an individual commit to a specific non-COW drive will still return the appropriate error (-ENOMEDIUM if eject / not present, -ENOTSUP if no backing file). Reported-by: Jan Kiszka <jan.kiszka@web.de> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22block: implement BDRV_O_UNMAPPaolo Bonzini
It is better to present homogeneous hardware independent of the storage technology that is chosen on the host, hence we make discard a host parameter; the user can choose whether to pass it down to the image format and protocol, or to ignore it. Using DISCARD with filesystems can cause very severe fragmentation, so it is left default-off for now. This can change later when we implement the "anchor" operation for efficient management of preallocated files. There is still one choice to make: whether DISCARD has an effect on the dirty bitmap or not. I chose yes, though there is a disadvantage: if the guest is buggy and issues discards for data that is in use, there will be no way to migrate storage for that guest without downgrading the machine type to an older one. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-02-22block: complete all IOs before .bdrv_truncatePeter Lieven
bdrv_truncate() invalidates the bdrv_check_request() result for in-flight requests, so there should better be none. Cc: qemu-stable@nongnu.org Signed-off-by: Peter Lieven <pl@kamp.de> Reported-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>